Hammer drill



Dec. 8, 1953 E. TOPANELIAN, JR

HAMMER DR ILL Filed Feb. 9, 1952 2 Sheets-Sheet 2 060E mdfi 00H. v 0;

INVENTOR.

paw) T PfNLI:AN,JR

+1 16 ATTQRNXY Patented Dec. 8, 1953 HAMMER DRILL Edward ,Topane ia Jn, ittsbur h, .Pa. assi nnr tohGulf Research & Development Company, rit sburs e ist am n a on o De w re Application February 9, 195.2, Serial No. 27 0,807 3.0laims. (01. 255 -4 1) .1. r This invention relates to well drills and-more particularly to a deep-well drill' combining the advantageous features of rotary and percussion drill mechanismsj object accomplished by my invention is the provision of a well fdrill which combines in-a novel manner the more desirable'ieatures of "rotary and percussion types of drills. A further object accomplished bymy' invention is the provision of a well drill having increasedefiectiveness against hard rock formations. Another object accomplished by my invention is the provision era drill o'f the character describfifi, having ncorporated therein 'a";fluid'-operated mechanism without substantially interrupting the *fiow- I of fluid through the bit. t sun f-urtheroloject accomplished by my invention is the provision of a well drill of suchdesig'h that the effect of hydraulichammer is diminished,'fbut advant ageously used in some degree toI'act-uate a hammer mechaiii'smwhi'ch strikes percussive blows to thedrill hit.

for delivering "percussive blows to the drill bit able weight so as to sep arately impart effective percussive'blow's to the drill bit. A still further object of myinvention the provision of 'a harn- .mer drill in which the val'vingelement itself may :act as [a' ram andi npa-rt percussive hlows to the drill bit. A still further object accomplished by my invention is the provision of a hammerdrilllin which upward motion of the valvihg element arrested byhydraulic action and inwhichthe va'l-ving eleme'n-tstri-kes a useful blow at thje end of its downward tra 'vel. Still another obj ectagcom-plished by myinvention is the provision of a percussion drill which will operate with reatively light weight on {the formation "bein gr l ed. Still another object aocomplish'ed hy vention i the ew Of M rx-pe cussion.t ne well i l simp v d tenden t dril straight hole and having holeistraighteriing properti s- S l an he oliie taqcompli hedih my n is the. p ovision q arctiy-ne sussion 1 type jwell drill of extremely simple design. A r, obje t fac' l ib i hsd. by .my invention is the provis-ion of a harnmer drill mechanism of such design thata grparts he made large.

eavyg simpie, andrugged. wherebylh eak semi fn rtsand'shutd wri .Qf t e "i -s t t y se se My invention is illustrated in the drawings acthereof, and in which Fig. 1 is a longitudinal section taken through the upper portion of a preferred embodiment of my drill;

Fig. 2 is a longitudinal section-taken through the intermediatelportionofthe drill of Fig. 1

Fig. 3 is a longitudinal section taken through the lower portion of the drill of'Fi'gs. 1 and 2 showing the drill bit attached thereto; and

Figs. 41120 :10 inclusive are diagrammatic representations illustrating various phases 'during the operation of my drill.

Reference is made to the drawings in which like numerals indicate the same element in the 'variousviews and diagrams. In Fig. 1, adapter 1 serves .to connect the drill assembly *with a' drill pipe .(not shown'),"-the' latter having a central passage as is conventional for supplying drilling fluid. Adapter i is provided with a central passage2 for the purpose of supplying drilling fluid under pressure into the drill mechanism. Adapter I is screwed into the drill housing 3 by threads .5 extends into'th'e housing =3 with an annular clearance .6 :between them; Openings 1' permit drilling fluid to pass fro zn -the passage 2 into the annularjspace l6. The lower e'nd'of passage 2 is plugged,'the plug 8 :h'eing either screwed or welded in place and having arelatively small ori- .ficesg5fl and spherical depression 5| on its upper surface. Arubberor steel ball 52 may rest in'the spherical depression 51 and serve to close the orifice 50; The function of the balljand orifice .Willbe explained i ater;

The extreme iowerend of adapter 1 is further reduced in diameter as atfs, andcarries thereon atuhe 10 against which a tight seal is provided .;by Caring 1 The tube 10 held-in place abutting the shoulder o bytwop-arallel pins -l-Z aiid -l2f-ai 'which are inserted throrigh thew a-ll of tuhe JD from the outside {thereof and which engage grooves intadapter' i. Both ends of pins 12 and ;l;2.-La exten'd beyond the "tube H! sufiiiently "so ,zthat the outers'housin'g 3 will prevent their coming out while the assembly is inside the housing. The pins l2 and l2-a are easily' removed W-henthe z a.s se m =b1y "is withdrawn from the housing 3 if neplacement orrepairiof'tube Libbecomes necessary. Th tube .19 at its .out5isie loweriend has fin er a weldedatoit and these rest on a line -1 4. T slinc rests on lin r 1.5. and-thispn line it his rs ='le ,;.t5 ,1and :|a6 have @995 izfii sprains ,irhese line srecei-re wear 3 and may be conveniently replaced when neces sary.

Below liner 16 there is a stop ring ll also fitting snugly in housing 3, but having a smaller inside diameter l8 than the liner iii. A spacer l9 lies below the stop ring I1, and below this is a guide 29 which is sealed to the inside of the housing 3 by O-rings 2| and 22' and which has a much smaller inside diameter than that of stop ring IT. The guide 29 rests on spacer 23.

The lower end of housing 3 is threaded for a bushing 24 which has a smaller internal diameter than housing 3, so that the various liners, space-rs, etc. are firmly clamped between shoulder 25 of bushing 24 and shoulder 9 of adapter I when the bushing is screwed up tightly into the housing 3. Thus bushing 23 holds in place spacer 23, guide 23, spacer i9, stop ring l7, liner l6, liner I5, liner i4, fingers l3, and tube 19, the latter abutting against shoulder 9 or adapter I.

It is apparent that liners l4, l5,

l6, and

spacers l9 and 23, as well as the stop ring H,

could be made integral with housing 3, the inside or" housing 3 being bored to the several internal diameters and shoulders as required. The construction shown is more convenient to manufacture because the housing 3 can be bored with a single internal diameter. The separate parts 14,15, 16, ll, 19, and 23 are easily finished to close dimensions and better surface finish and they provide the necessary shoulders or differences in diameter for the assembly. In addition, any one of these smaller parts may easily be replaced if it becomes worn.

Starting now at the lower, end of Fig. 3 there is shown a bit stem 23 which has a central passage 2? through which drilling fluid reaches the bit. A conventional drilling bit 46 may be screwed on to the bit stem 21 by means of threads 23. The drill bit 45 has a central passage 38 and is further provided with passages 49 connecting th central passage with the well bore to facilitate the removal of cuttings and chips therefrom by means of flushingaction of the drilling fluid. While a fish-tail type of bit is shown, the drill bit per se forms no part or" my invention and any type of bit may be used, including rock bits having rolling cutters. The bushing 24 is grooved at 29, and mating splines 30 on bit stem 26 engage the grooves 29 so that torque may be transmitted from the bushing 24 to the bit stem and bit. Instead of using splines and grooves, the rotary driving engagement between bushing 24 and bit stem 23 may have square, hexagonal or other equivalent shape. Accordingly, during drilling the entire assembly may be rotated from the surface of the ground by means of the conventional drill pipe (not shown) and this will rotate the bit 49. The bit stem 26 may slide in the bushing 24, the amount of longitudinal motion being limited by a split ring 33 mounted in a groove 32 in the upper end of the bit stem. When the bit stem 26 is at its lowermost position, the ring 3! abuts against internal shoulder 25. When the bit stem 26 is in its uppermost position an external shoulder 33 on the bit stem abuts against the lower end of bushing 24.

Situated above the bit stem 23 is an annular lower arm 34 whose outer diameter is a close sliding fit in guide 20. Lower ram 34 functions as a valve as will be explained. In my drill it may be made quite heavy and it functions as well as a blow-imparting means, in that its reciprocation adds to the percussive action of the drill as will become evident. The upper end or head of lower ram 34 is enlarged in diameter as at 35, the diameter 35 being larger than the opening E8 in stop ring it. The purpose of this relationship will also be explained later. The lower ram 33 has a central passage 36 to permit discharge of drilling fluid therethrough. The passage 36 is made small enough so that it functions as an elongated orifice in the fluid stream whereby the velocity change sets up a pressure drop across the lower ram 34. In this way a substantial downward pressure differential is caused to act on the lower ram 34 whenever the drilling fluid discharges through it.

While it is not necessary for the operation of my drill, under certain conditions of operation it is advantageous to place a spring 31 around the lower ram 34, the spring 31 abutting against the lower end of guide 20 and against a shoe 38 which is carried on the lower end of ram 34. The shoe 38 may be shrunk onto the ram 34, or

be heldthereon by other means, and is conveniently made replaceable as it receives considerable pounding during operation of the drill. The ram 34, being of considerable mass, normally moves downward by its own weight plus the pressure differential 0f fluid flowing downward in its passage 35, but the downward impetus of ram 34 may be further augmented by the use of spring 31.

On top of the lower ram 34 rests an elongate annular upper ram 39, having a central passage 40.- The latter may be larger indiameter than the passage 33 through the lower ram 34 in order to permit free flow of fluid through the passage 40. The outside diameter of upper ram 39 is smaller than the opening ll! of stop ring l'i in order to permit circulation of fluid through the annular space between them. Although it is not necessary for the operation of my drill, it has been found desirable to have the upper part 4! of ram 39 made slightly larger in diameter than the lower end thus providing a slight shoulder 41. The shoulder 41 provides a difierential area between the bottom and top of ram 39 so as to afford the fluid a lifting eifect on ram 39, which lifting effect should however be insufficient to overcome the weight of ram 39.

An annular space is provided between the outside of upper ram 39 and the liners l6 and I5 to provide adequate circulation of fluid. Lugs 42, three or more in number, may be welded to the outside of ram 39 and serve as guides sliding .freely on the inner surface of liner IE but allowing circulation of fluid between lugs. The lugs 42 serve to center the upper ram 39 in liner [6. The upper end of ram 39 penetrates the lower end of tube 10 and is of such diameter to slide freely into tube 59. A wear sleeve 43 may be pressed into tube [9 and have a slightly smaller mside diameter than tube ID. The upper end 4| of ram 39 is of proper diameter to form a sliding seal in the sleeve 43.

A short distance below the top of ram 39, there are provided one ormore radial openings 44 from the outside of the ram to the passage 49. When the ram 39 is in its lowermost position, it still partially penetrates the tube 1 0, but the openings 44 are no longer covered by the sleeve 43 of tube I0, and fluid communication is established between the annular space 6 and-the passages 49 and 36. The purpose of this is to permit drillingoff as will become evident later. The openings 44 also permit circulation of drilling fluid through the drill without activating the mechanism while the drill is being run into or out of the hole.

This hase of the operation is illustrated in Fig. '7.

- As soon as upward motion of lower ram 34 is arrested, the pressure fluid tends to separate the two rams, and indeed the upward momentum of the upper ram 39 tends also to lift it off the top of the lower ram 34. The upper ram 39 may continue to move upward a short distance. However, as soon las the upper ram 39 breaks away from the lower ram 34, the pressure fluid may escape downward through the passage 36 in the latter. The consequent release of upward pressure on the lower ram 34 allows it to drop of its own weight, and furthermore, the downward rush of fluid through its passage 36 effects a pressure differential which gives it further downward impetus. Accordingly, the ram 34 moves rapidly downward as illustrated in Fig. 8.

Shortly after lower ram 34 has started to move downward, the upper ram 39 also begins to move downward since there is no longer any pressure to raise it. Accordingly, the ram 34 and ram 39 both descend, though separated by some distance and with the lower ram 34 moving down somewhat faster than the upper ram 39 because of the aforementined downward forces which act on the lower ram but not on the upper ram. Eventually, the lower ram 34 strikes the top of the bit stem 26 imparting a blow thereto which blow is transmitted to the drill bit 46. This phase is illustrated in Fig. 9. 39 at this phase is still falling.

A short interval after the lower ram 34 has struck the bit stem 26, the upper ram 39 strikes the top of ram 34, and this blow is transmitted through ram 34 to the bit stem and thence to the drill bit 46. This represents the completion of a cycle of operation, as shown in Fig. 10.

The mechanism is now (Fig. 10) in the same configuration as it was in Fig. 5 and is therefore ready to repeat the cycle of operation. Each cycle results in two percussive blows being struck on the formation through the drill bit 43. Due to the fact that the entire drill assembly is continually also being slowly rotated, the various percussive blows exerted on the formation being drilled will be made at points angularly displaced from one another by several degrees, so that the drill bit will chip out the formation between successive points of impact. Fluid discharged from the mechanism will act as flushing agent and will be substantially continuously discharged from the bit 46 into the well bore and serves to carry the chips to the surface of the well. Continuous operation of the drill will therefore completely remove material from the bottom of the hole and result in advance of the drill through the formation.

As stated above my hammer drill will operate without the use of spring 31 and spring 45, but the use of these springs has been found to increase the frequency of operation. This is particularly desirable when hole conditions prescribe drilling with very heavy mud in which the mechanism tends to become sluggish. Successful operation with light to medium weight mud and without the use of the springs 31 and 45 results in longer tool life.

Fig. 1 shows a narrow passage 50 in the plug 8 at the lower end of the passage 2 of adaptor 5.

The passage 50, together with the omission of ball 52, permits the drill to accommodate larger fluid circulation rates which are required when drilling certain types of formation. The flow of fluid through passage 50 by-passes the drill mechanism and is effective for flushing chips or The upper ram 5 detritus out of the borehole in addition to the fluid normally discharged through the drill mechanism. It is apparent that the diameter of passage 50 may be of calculated size such that it acts as a by-pass orifice but does not seriously interfere with the operation of the drill mechanism. Whenever it is desired to close the passage 50, the ball 52 may be dropped from the surface to seal the opening without pulling the tool from the well. In this manner the circulation rate may be controlled. It has also been found desirable to start a new drill with the passage 50 open, and after the drill mechanism has become worn the ball 52 may be dropped to close passage 50 and in this way leakage caused by wear may be compensated.

As previously stated, one of the advantages of my hammer drill lies in the fact that the valving ram 34 as well as the upper ram 39 delivers a percussive blow and these are in rapid succession. By making use of the impetus of the valving ram 34 as well as that of the upper ram, my drill attains a higher degree of effectiveness than if one ram alone supplied the percussive action. The timing of the two blows may be adjusted by the size of the passage 36 through the lower ram 34, since the smaller this passage is made the faster the ram 34 is kicked down by the discharging fluid. Additional adjustment of the timing may be effected by adjusting the relative stiifnesses of springs 31 and 45 when theseare used. My drill permits the two blows to be made comparable because the lower ram 34 may be made of a mass comparableto that of the upper ram 39.

An important characteristic of my drill is the fact that it achieves hydraulic balance. By this I mean that the hydraulic actuating pressure is not exerted on the bit stem 26 or on the bit 46. Hence the percussive action will take place with comparatively little weight on the bit. The guide 20 serves as a restriction above which the fluid pressure is higher than below by an amount required to actuate the drill mechanism. The restriction 23 forms a housing-supported barrier between the high-pressure fluid required for hammer operation and the much lower fluid pressure required to circulate fluid through the ports in the drill bit. Therefore, there is but very little pressure tending to eject the bit stem 26 and bit 48 from the end of the housing 3, and accordingly the drill may be operated with the bit applying to the formation between percussive blows little more than the weight of the bit 46 and bit stem 26, all other weights and pressures being supported from the surface through the drill pipe and housing 3. This characteristic of my drill results in the ability to drill straight hole under adverse conditions which usually require that the bit be rotated with only light weight on the formation. On the other hand, by lowering the drill pipe from the surface so that a substantial part of the drill-pipe weight rests on the shoulder 33 (Fig. 3) any desired larger weight may be exerted on the formation. Furthermore, the percussive action of my drill is entirely independent of the weight which is carried on the formation.

A further advantage of my drill lies in the fact that when the drill is set on bottom the telescoping bit stem forces the lower ram upward out of any accumulation of sand, mud or other debris which may have packed around the top of the lower ram while the drill was inactive during the trip into the hole. This upward motion of the lower ram breaks any such accumulation and permits the operating pressure to 'act on the is used to designate valving element 34, and the term upper ram is used to designate the ele-- ment 39, but it is to be understood that the names given these and other elements shown are descriptive and that other equivalent shapes may be given these elements and still remain within the scope of the claims.

What I claim as my invention is:

1. A fluid-operated well-drilling mechanism comprising a tubular housing, an inverted cuplike cylinder longitudinally mounted in said housing, meansaffording operating fluid access to the interior of said housing below said cylinder, an elongate annular upper ram slidably disposed in and sealed against the inside of said cylinder and having a longitudinal central passage, an internal constriction in said housing below said upper ram and of diameter smaller than said upper ram, an elongate annular lower ram slidably disposed in and sealed against said constriction and having a longitudinal central passage and having spring-retaining means on the lower end of said lower ram, a compression spring between the lower side of said constriction and said spring-retaining means, means affording operating fluid access to the upper end of said lower ram, and a bit stem slidably disposed in and sealed against said housing and having a longitudinal central passage.

2. A fluid-operated well-drilling mechanism comprisinga tubular housing, an inverted cuplike cylinder longitudinally mounted in said housing, means affording operating fluid access to the interior of said housing below said cylin der, an elongate annular upper ram slidably disposed in and sealed against the inside of said 10 cylinder and having a longitudinal central passage, a compression spring inside said cylinder above said upper ram, an internal constriction in said housing below said upper ram and of diameter smaller than said upper ram, an elongate annular lower ram slidably disposed in and. sealed against said constriction and having a longitudinal central passage and having springretaining means on the lower end of said lower ram, a compression spring between the lower side of said constriction and said spring-retaining means, means affording operating fluid access to the upper end of said lower ram, and a bit stem slidably disposed in and sealed against said housing and having a longitudinal central passage.

3. A fluid-operated well-drilling mechanism comprising a tubular housing, an inverted cuplike cylinder longitudinally mounted in said housing, means affording operating fluid access to the interior of said housing below said cylinder, an annular upper ram slidably disposed in and sealed against the inside of said cylinder and having a longitudinal passage, an internal constriction in said housing below said upper ram and of diameter smaller than said upper ram, an annular lower ram slidably disposed in and sealed against said constriction and having a longitudinal pasage in register with the passage in said upper ram, said passage in said lower ram being of diameter to effect reduction of pressure of operating fluid in flowing therethrough, means aifording operating fluid access to the upper end of said lower ram, means limiting the upward movement of said lower ram, and a bit stem slidably disposed in and sealed against said housing and having a longitudinal passage in register I with the passage in said lower ram.

EDWARD TOPANELIAN, JR.

Name Date Topanelian Dec. 25, 1951 Number 

